Update for anyone that may be looking in the future. The high country is drilled and tapped for 6-48. The two ultralite I have are 8-40. Not sure why don’t stick with one size?

I got lucky and when I ordered my EGW base, I paid the extra 5 dollars for the extra screws. It came with both sizes so I was set and ready to go.

Also got lucky and the rifle loves my hand loads that were loaded for my sons rifle. Shot a 5 shot 1/2 group out of the gates. No need to work up a load and can get straight to bear killing. Pretty impressed with this rifle so far.